1. Field of the Invention
The present invention relates to a vacuum cleaner and, more particularly, to a cordless vacuum cleaner using an internal battery as a power source.
2. Related Background Art
The basic construction of a vacuum cleaner is generally such that a suction force of an electric blower is allowed to act on a suction opening facing a floor to be cleaned, air including dust sucked through the suction opening is passed to a dust collecting unit, and dust is collected and removed by a dust collecting filter. The collected dust is accumulated in the dust collecting unit. A rotating brush which slides on the floor is mounted at the suction opening to stir up dust on or hiding in the floor, thereby increasing the dust sucking efficiency. The dust collecting unit is detachable so that the accumulated dust can be discarded and the dust collecting filter cleaned or replaced.
When the suction opening is lifted and is apart from the floor, the rotating brush rotates in idle at high speed, and it makes noises and is also dangerous. Consequently, a safety switch for detecting that the suction opening is apart from the floor face and stopping the rotation of the rotating brush has been proposed.
A cordless vacuum cleaner using an internal battery as a power source has been proposed, with a rodlike handle attached to the body of the vacuum cleaner. The body includes a rotating brush, a dust collecting unit and an electric blower unit which are integrally attached to a suction base in which a brush chamber is formed to reduce the size and weight for easy use.
In such a small vacuum cleaner, since the dust collecting unit has a small size, the volume of the dust collecting box is small, and the area of the dust collecting filter is also small. Since it therefore becomes necessary to relatively frequently discard dust accumulated in the dust collecting box and clean the dust collecting filter, it is desirable that attaching and detaching operations of the dust collecting box be easy. Moreover, in the attached state, it is desirable that any air duct joint is sufficiently airtight, and that resistance to the ventilating air flow is low.
Since waste thread, hair and the like twine around the rotating brush, the rotating brush has to be taken out to remove them. It is therefore also desirable that the rotating brush can be easily exposed or attached/detached.
It is also desirable that dust collected by the dust collecting filter can be efficiently accumulated in a small dust collecting box.
If the capacity of a battery in such a vacuum cleaner is increased so as to permit continuous long-time use, the vacuum cleaner becomes large and heavy, and its operability or handling becomes difficult.
On the other hand, Japanese Unexamined Utility Model Publication No. 61-101698 discloses an electric blower.
The electric blower has a skirt for changing the direction of fluid flowing in the radial direction from the center of an impeller fixed to a motor shaft to the axial direction of the motor shaft. The skirt is on the periphery of the impeller.
By the structure, the direction of air flowing out from the periphery of the impeller can be changed to the axial direction in the impeller. The size of the impeller can be therefore increased with respect to a fan cover of the same size. For obtaining the same characteristics, therefore, the rotational speed can be reduced and the noise level, influenced mainly by the rotational speed, is accordingly suppressed.
Japanese Unexamined Utility Model Publication No. 50-64201 discloses a technique for improving the efficiency of a submergible motor pump.
The submergible motor pump has a pump casing formed in an angular shape in cross section. A volute discharge opening of the pump is disposed in the apex portion of the angular shape. A circular motor casing is disposed substantially in contact with a side of the pump casing and the gap between the casings is extremely narrow.
Because of the structure, water discharged from the volute discharge opening reaches a pump discharge opening without interfering with the neighboring volute, so that friction loss and collision loss are reduced.
In a floor moving type or upright type vacuum cleaner, since the size of the body can be flexibly determined, the size and the rotational speed of the electric blower are easily set. The vacuum cleaner in which the size of the body is reduced and an electric blower having an electric motor and a blower and a dust collecting unit are provided in the body of the suction opening casing has, however, problems in that the outer, diameter of the blower cannot be increased and the rotational speed of the blower cannot be increased.
In the floor moving type or upright type vacuum cleaner, since the ventilating air loss in an area from the suction port to the inlet of the electric blower is large, in order to enhance the dust collectability, a high vacuum state has to be created. Consequently, a centrifugal impeller has to be used in the blower. This disturbs the miniaturization of the vacuum cleaner.
According to the conventional technique disclosed in Japanese Unexamined Utility Model Publication No. 61-101698, the outer diameter of the impeller is large and the size of the vacuum cleaner is large. This has a problem in that, when the volume of air is increased, the air is choked in a curve and the performance deteriorates.
Japanese Unexamined Utility Model Publication No. 50-64201, discloses a vacuum cleaner having an electric motor, a blower, and a dust collecting unit provided in the body of a sucking opening member. There is a large dead space in the suction opening member, so that the vacuum cleaner is large. When the air flowing from the blower is used to cool the electric motor in order to reduce the size of the vacuum cleaner, there is a problem in that the motor cannot be effectively cooled.
It is therefore a first object of the invention to provide a small, easy-to-use, high-performance vacuum cleaner.
A second object of the invention is to facilitate an operation of attaching/detaching a dust collecting box and an operation of attaching or exposing a rotating brush.
A third object of the invention is to maintain the air tightness at a joint portion of an air duct when the dust collecting box is attached.
A fourth object of the invention is to provide an air duct in which a ventilating air resistance is low.
A fifth object of the invention is to efficiently collect dust in a small dust collecting box.
A sixth object of the invention is to provide the body of a vacuum cleaner with a good weight balance.
A seventh object of the invention is to improve the handling of the vacuum cleaner by devising a form of housing for batteries, i.e., a power supply unit.
Specifically, a power supply unit is efficiently housed in a handle, assembling performance is improved, backlash in the handle is prevented, and deterioration in the operability due to the heavy weight of the power supply unit is prevented.
An eighth object of the invention is to provide a small, light and highly-efficient electric blower in a vacuum cleaner having a structure such that the electric blower, comprising an electric motor and a blower, and a dust collecting unit are provided in the body of a suction opening member, providing a small, light vacuum cleaner having high dust collectability.
According to the invention, there is provided a vacuum cleaner having a body integrating a rotating brush, a dust collecting unit and an electric blower unit with a suction opening casing in which a brush chamber is formed. The brush chamber can be covered with a suction opening cover on the front side portion, in front of a partition wall provided upright in the rear portion of a suction opening. The rotating brush is housed in the brush chamber, and the dust collecting unit and the electric blower unit are arranged in the lateral direction in the rear portion. The rotating brush is rotated by a driving motor in the electric blower unit. The dust collecting unit has a cup-shaped dust collecting box having a suction opening in a side face and a dust collecting filter housed in the dust collecting box. The dust collecting box can be detachably attached to the suction opening casing so as to lie down by using a dust collecting unit receiver provided upright at the rear end of the suction opening casing as a support. The suction opening of the attached dust collecting box is securely communicated with the rear end of a suction duct which is formed in the partition wall and is opened to the brush chamber. The opening end of the dust collecting box is securely communicated with the communication passage to the electric blower unit. Thus, by having this arrangement of the components, the small, easy-to-use, high-efficient vacuum cleaner is provided.
The suction opening cover has a control knob for a retaining mechanism for retaining the dust collecting box and the suction opening cover on the suction opening casing. This makes the attaching/detaching operation of the dust collecting box and the suction opening cover easy. The collected dust in the dust collecting unit can be discarded, and the rotating brush can be exposed or detached to be cleaned.
In the dust collecting unit, a step is formed on the peripheral face of the dust collecting box and comes into contact with a step in the suction opening casing in order to stabilize the dust collecting box in an attaching position when the operation of attaching the dust collecting box is performed in the vertical direction.
The dust collecting box in the dust collecting unit is formed in a cup shape having a side face inclined so that the bottom has a small diameter, and the suction opening is formed in the inclined side face.
The suction opening is in the lower half portion when the dust collecting box is attached.
The dust collecting unit is constructed so that the dust collecting box is attached/detached in the vertical direction. A packing is attached to the end face of the opening of the dust collecting box with an inclined face whose upper side is thick and whose lower side is thin and recedes. An end face of the communication passage is formed as a flange having an inclined face whose lower side is thick and whose upper side is thin and recedes.
By such specific construction, the air tightness at the joint of the air ventilating duct is not lost when the duct collecting box is attached, and an air ventilating duct in which resistance to ventilating air is low is provided.
In the dust collecting unit, the dust collecting filter is housed eccentrically in the dust collecting box.
Specifically, the dust collecting filter is housed eccentrically so as to be close to the suction opening of the dust collecting box or so as to be apart from the suction opening, thereby efficiently collecting dust into the small dust collecting box.
By providing a handle joint swingable so as to surround the communication passage provided between the dust collecting unit and the electric blower unit, a good weight balance of the vacuum cleaner body is obtained.
Further, according to the invention, a vacuum cleaner is provided comprising: a vacuum cleaner body in which a rotating brush, a dust collecting unit, and an electric blower unit are integrally attached in a suction opening casing in which a brush chamber is formed; and a rodlike handle connected to the vacuum cleaner body, the rodlike handle being constructed by a hollow member, and a plurality of batteries are housed in series in the hollow member, thereby efficiently housing the power supply unit.
The plurality of batteries are covered with a heat contraction tube so as to be integrated in a rodlike member and housed in the hollow member, thereby improving the assembling performance.
Further, an arbitrary number of backlash preventing packings, which are elastically made by using a foamed resin, are interposed between the rodlike member and the hollow member, and each of the outer ends of the plurality of batteries arranged in series is pressed via a protection packing, thereby preventing the batteries from rattling in the handle.
The dust collecting unit and the electric blower unit are arranged in the lateral direction on the back side of the brush chamber in the suction opening casing and are connected to each other via a communication passage. A handle joint is provided so as to surround the communication passage, and the rodlike handle is connected to the handle joint, thereby preventing the operation from becoming unstable due to the weight of the batteries.